It is frequently necessary to automatically dispense a predetermined quantity of material into a container. Scales, balance beams, or electronic load cells are commonly used to measure the weight of the container when empty, and the combined weight of the container and a quantity of material that has been dispensed into the container.
A load cell, including a plurality of strain gauges (e.g., arranged in a full bridge configuration), is often used to provide an electrical signal that is a function of beam. The electrical resistance of the strain gauges changes as the strain gauges are elongated or compressed due to a change in the weight applied to the platform. The changes in resistance are converted by an electronic processing device or other suitable means into a voltage, current, or other signal that is a function of the applied weight. This signal may be entered into a control system that can be programmed to calculate the weight applied to the platform. Unfortunately, strain gauge type load cells are quite costly, difficult to use, and are mechanically fragile. For example, the strain gauges are easily damaged when the platform is overloaded or excessively stressed, necessitating the tedious and expensive process of replacing the strain gauges.